Max- Kickstarter is your best bet. Just start a campaign to buy a 3D printer and give each contributor a small % of time on the machine. You host it in your lab and provide access to it over the web. You probably need to add the cost of an 'intern' to manage the hosting but I bet you could get a good deal from a manufacturer as part of the campaign. Try it! (Or find a volunteer to do it for you...)

Another thought is that you could find a local hackerspace or 3d printer club. Most hackerspaces have a 3d printer now and many offer daily rates for equipment use (as opposed to a monthly membership). The advantage here is that there is probably a knowledgeable person to walk you through the nuances of the machine.

@Caleb: ...and several for under $500. Check out Solidoodle for that price range.

Oooh!!! That does look REALLY tasty!!!

When I was in Norway I saw a 3D printer at the university of Oslo that allowed you to print with two materials -- one could be easily disolved away -- this let you create things like interwined parts -- I'm guessing the Solidoodle doesn't have this capability?

Generally, no this type of printing does not allow for a material that disolves. There have been a few experiments with it, but nothing in the commercial market yet. There are a couple printers out there that can print in 2 materials/colors right now though.

aside from colored plastic there is a wood material as well as some glow in the dark material!

If you want to print fully moving parts, you'll need to bump up to the 10k plus range and get a much fancier printer that doesn't lay down layers of hot plastic.